Valve mechanism for explosive engines



1935. A. A. SMITH 2,011,124

VALVE MECHANISM FOR EXPLOSIVE ENGINES Filed Aug. 25, 1933 jgg gzgmm js "ii", {13 5 20 )1 at an 2572/07 d. 5772657 2.

, Patented Aug. 13, 1935 PATENT OFFICE]:

VALVE. MECHANISM FOR EXPLOSIVE ENGINES Amiisi A. Smith, Chicago, 111. Application August 25, 1933, Serial No. 686,786

11 Claims. (01. 123-90) My invention relates to internal combustion engines, and more particularly to the valve i v the; opening and closing actions of the same, and

mechanism therefor, and my main object is to provide a novel valve which will create a considerable improvement in the efiiciency of the engine.

A further object of the invention is to utilize the standard poppet valve with a development which maintains the valve in open position much longer than usual, thereby providing a clear passage for the incoming or outgoing gasesfor a longer time. l

A still further object of the invention is to procure the opening of a passage for the gases entering or leaving the engine cylinder. much quicker than under the present practice, yet without vide an installation which requires less room in the cylinder head, enabling the same to be made with a smaller valve pocket.

With the above objects in View, and any others thatmay suggest themselves from the specification and claims to follow, a better understanding 1 of the invention may-be had by reference to the accompanying drawing, in which- Fig. 1 is a section of a typical internal combustion engine, showing the novel valve mechanism in closedposition; J i

Fig. 2 is a view similar to Fig. 1, showing-the valve mechanism inopen position; and

Figs. 3, 4 and are, respectively, enlarged sections on the lines 33, 4-4 and 5'-.5*of Fig. 1.

In the analysis of poppet valve actionin the typical internal combustionengine, it is found that the greater movement of the valve entails practically always changing in area and is generally restricted in cross section. 1 This fact materiallyafie'cts the velocity of the medium in the passages and reduces the efficiency of the engine. 1 To remedy this condition, the cams operating the i valves would have to be made considerably steeper, which would make it more difficult to raise the valves and would tend to jam or distort the stems thereof. It has therefore been my intention to provide a valve mechanism which by means of the movable seat mentioned enables me to impart only half the stroke to the valve, yet

secure the full opening thereof, so that I am able to use a flatter camarid so keep the valve open much longer than heretofore.

In carrying out the invention, a specific refer 'ence to the drawing shows the engine cylinder at It], the piston at H, the cylinderhead at l2, the poppet valve therefor at E3, the valve'pocket-at [4, the valve guide at E5, the valve port at It, the valve spring at I1 and the cam shaft at l8.

In the novel embodiment, the valve pocket I 4 is cylindrically machined to ailord the disposal of a sliding, piston-type of seat IQ for the valve head I3a. As shown in Fig. 2, theseat i9 is chamfered on the inside as is the usual practice to seatthe valve at 130.; and the wall of the seat-piston is provided with rings Ifia to sealit in the pocket. I 4. I prefer to provide the stem of the valve l3 with a roller I36 atits lower end to ride on the shaft l8 and the cam l8a thereof. When the valve is seated, as in Fig. l, theupper part of its stem seats in an internal. shoulder lid of the valve guide 1 I 5, from which region downward the valve stem is somewhat reduced in diameter, as shown. The shoulder l5a merely forms a limit for the descent of thevalve, in case the seat 19 should be removed or lowered for any reason, and such shoulder is calculated not to form a stop before the valve head l3a is fully seated on its seat. l

Sufficient clearance is had between the origin of the valve stem reduction and the shoulder a, as well as'between the roller I31!) and the cam shaft 18, to allow for the very slight fall of the 35 valve when it is ground. Of course, where the valve requires refacing or re-seating, the guide shoulder He will require cutting down somewhat. In such a case the valve itself could be altered to include an adjustable tappet arrangementattthe bottom for the necessary clearance from the cam shaft and its cam, or replaced by a valve made with such an arrangement. 1 i

It is my intention that the seat I I9 descend when the valve l3 rises, in keeping with the 5 principle of giving the valve only half the usual stroke while forming a passage of the same cross section as with a standard valve. For this purpose, I extend the seat piston l9 downwardly with a set of four stems 2a, which pass slidably' through guides 29a formed in the cylinder casting. The stems 2!! connect with the upper end Hit of a rectangular member 2i extending in a downward direction, such member having a base 2|b boosted from underneath by a. coil spring 22. The base 2lb has companion ledges 2H0 upon which bear twin cams i811 carried by the cam shaft it. Thus, while the cam l8w bears upwardly on the valve stem I3 against the tension of the valve spring H, the twin cams lSb bear downwardly upon the member 2| against the tension of the spring 22, the effect of these actions being to raise the valve head 113a While its seat i9 is lowered.

Owing to the fact that the valve head and seat separate simultaneously to create a given opening, only half of the usual stroke is necessary for either the valve or the seat, enabling the cams Mia and I81) to be made lower and therefore much flatter than usual. I can thus procure the opening of the valve passage in about 45 of crank shaft travel, then have a full opening for 90, and the closing for the final 45 of the 180 valve-operating interval.

It will be obvious from the above description that I have provided avalve mechanism which in opening the valve more quickly and keeping it open much longer than usual will considerably improve the charging and scavenging of the cylinder, and thus procure greater power and speed. Further, the more gradual opening of the valve will greatly reduce the detonation and noise of the engine. Further, the action and opening procured by the novel valve will permit it to be made of smaller diameter, therefore requiring a smaller valve pocket. Further, the opening and closing actions of the novel valve will be more certain because of the shorter and more gradual climb and descent over the cam, making the valve more reliable for the functions mentioned than valves of the present type, where the control is in the nature of an impact, tending to continually keep the valve off its seat. The full and certain closing of the valve is also insured by the fact that the descent thereof is through a much shorter space than usual, thus facilitating early seating. Finally, it will be apparent that the parts entering into the novel valve mechanism are in keeping with standard engineering practice and devoid of delicate elements or complicated mechanisms, enabling the valve to operate efiiciently for long periods without undue attention or repair.

I claim:-

1. An engine containing a valve, a pocket for the latter, a seat for the valve and slidable in the pocket toward and from the head of the valve, an engine'camshaft, and means controlled by the latter to open the valve and retract the seat simultaneously.

2. An engine containing a poppet valve having a valve head, a valve stem and a valve pocket: a seat for said valve slidably mounted in said pocket for movement towards and away from said valve head, cam contacting means on the free end of said valve stem, a cam shaft, a cam on said shaft for contacting said valve stem and actuating said valve head in one direction, an extension of said sliding seat, said extensionextending alongside of said valve stem and beyond the end thereof to a point beyond said cam shaft, cam contacting means on the end of said extension, and a second cam means on said cam shaft and arranged to contact said extension simultaneously with the contact of the first cam with said valve stem.

3. The structure of claim 2, said second named cam means being on the opposite side of the camshaft from said valve cam and staggered from the latter.

4. The structure of claim 2, said second named cam means comprising spaced cams on the opposite side of the camshaft from saidvalve cam, and follower elements on the extension for the spaced cams, said elements by being spaced accordingly affording clearance for the valve cam.

5. The structure of claim 2, and a spring urgmg the extension into engagement with said second named cam means.

6. The structure ofclaim 2, the extension comprising rods directed from the seat-cylinder, bearings in the valve pocket for the slidable passage of the rods, and a rectangular frame carried by the rods as a follower. 1

7. An engine containing a poppet valve having a valve head, a valve stem and a valve pocket; a seat for said valve slidably mounted in said pocket for movement towards and away from said valve head, cam contacting means on the free end of said valve stem, an extension of said seat, cam contacting means on said extension, a cam shaft, and separate cams on said shaft to simultaneously engage both cam contacting means and impart a positive separating movement to said valve and seat simultaneously.

8. An engine containing a poppet valve, means for actuating said valve in one direction, a seat for said valve, means acting simultaneously with said valve actuating meansfor retracting said seat in a direction opposite to that of said valve from the location where the valve normally seats upon it, a valve stem for said valve, a bearing for said stem, 2. stop in said bearing, and a portion of said valve stem being formed to engage said stop and limit the movement of said valve and stem in the seating direction.

9. An engine containing a poppet valve, means for actuating said valve in one direction, a seat for said valve, means acting simultaneously with said valve actuating means for retracting said seat in a direction opposite to that of said valve from the location where the valve normally seats upon it, a bearing for the slidable passage of the valve stem, said stem being formed with a shoulder, and a seat formed in the bearing and effective to engage said shoulder and prevent excessive ionovement of the valve beyond its seating posi- 10. An engine containing a valve, said valve having a head and a slidable seat therefor, means synchronized'with said engine and positively and automatically moving said head and valve seat simultaneously in opposite directions to open said valve.

11. An engine containing a valve, said valve having a head and a slidable seat therefor, and means operated by and synchronized withsaid engine for automatically moving said head and seat'simultaneously in opposite directions to open said valve.

ANTHONY A. SMITH. 

